Leopold sturzwage



(No Model.)

L. STURZWAGE.

PIANO MECHANISM.

No. 592,840. Patented Nov. 2,1897.

UNITED STATES a'rnnrr rites,

LEOPOLD STIIRZWAGE, OF MOSOOVV, RUSSIA.

PIANO MECHANISM.

SPECIFICATION forming part of Letters Patent No. 592,840, dated November2, 1897.

Application filed June 22, 1897. Serial No. 641,804. (No model!) To aZZwhom it may concern.-

Be it known that I, LEOPOLD STiiRzWAeE, a subject of the Emperor ofRussia, residing at Moscow, Russia, have invented certain new and usefulImprovements in Piano Mechanics, of which the following is aspecification.

The present invention relates to repeating mechanism for grand pianosand involves the peculiar construction of the jack and fly-jack, bymeans of which an even, light, and noiseless stroke or blow, as alsoreliability of repetition, is obtained.

In order to render the present specification more easilyintelligible,reference is had to the accompanying drawings, in whichsimilar letters of reference denote similar parts throughout the severalviews.

Figure 1 is a side elevation of the device, showing the hammer down.Fig. 2 is a similar elevation drawn to a larger scale with the hammerraised, and Fig. 8 a front elevation of Fig. 2.

The jack a is pivoted at a and provided at one end with a cushion a onwhich the stem 1) of the hammer rests, said jack carrying the fly-jack cat the opposite end, having its pivot arranged approximately over therigidly-fixed striker-pin d. The end of the fiy-jaok is bifurcated andembraces the jack a, enabling a small spring e, mounted on the jack a,to pass between the bifurcations and engage a cord-eye fastened on thelower surface of the projecting foot 0 of the fiy-jack. Theupwardly-extending surface of the foot 0 is provided with a cushion andis adapted when the key is struck to engage the fixed stop f, which isadjustable by means of a screw f and operates to throw the fly-jack outof engagement with the knob b of the hammer-stem. The upper part of thefly-jack is narrowed to enable it to pass through an orifice g of therepeater-lever g, in which orifice it has sufficient play to preventfriction. Above the orifice the fiy-jack is again widened, so that itsupper edge is of the same width as the knob or projection b on the stemof the hammer and also as the raised shoulder g of the repeater-lever g.

lVhen the key is struck, the hammer b is first raised by the fiy-jack 0until it has nearly attained a horizontal position, when the knob 1)passes onto the shoulder 9 Fig. 2, the fly-jack being thrown out ofengagement by the stop f without causing the slightest fricthe fly-jackc from being thrown too far back from the knob Z2. The said screw 2'also forms a stop for the lever g itself after it has been thrown out ofengagement. The spring 7a, which is bent round at an angle, isadjustable in the jack a by means of a screw Said spring engages acord-eye fastened to the lever g. The adj Listing-screw enables an exactadjustment of the spring is for the heavier bass and lighter sopranohammers.

The raised shoulder g of the repeater-lever enables the fiy-jack to bemade broader at its upper end, which has the effect of preventing thesame from getting pressed into the knob 11, as has hitherto been thecase, thus causing considerable friction on the disengagement of thefly-jack. Both the jack and the repeater-lever will thus be disengagedwithout causing any friction whatever, so that no noise whatever can becaused by the present mechanism, since the springs will work entirelynoiselessly in their cord-eyes.

I claim as my invention- 1. In a repeating mechanism for grand pianosthe combination of the jack a with the repeater-lever g mounted on thejack and having a raised shoulder g and an orifice g before saidshoulder, and a fiy-jack c mounted on the jack a, the said fly-jackpassing through the orifice g of the lever g and having its upper edgewidened to the Width of the knob b of the hammer-stem, substantially asdescribed.

2. In a repeating mechanism for grand pianos the combination of the jack(1 the repeater-lever g with slot g end shoulder g and the fly-jack 0having a widened upper edge, with the stop f disengaging the fiy-jack inits upward movement and the stop c screwed in the repeater-lever g, thestop c limiting the backward movement of the fly-jack, substantially asdescribed.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

LEOPOLD STURZWAGE.

Witnesses:

. Aueusr MtIHLE,

WLADIMIR ZIOLECKI.

